Hi RasmusK
Please feel free to comment or post questions/ suggestions!I'm now living in Hokkaido.
Just wanted to let you know my few comments.
When you rent a car near Shin-Chitose Airport, visit a more economical (less popular) shop such as Ones' Rent-a-car, Choinori Rent-a-car, and Niko-Niko Rent-a-car. Usually, at these low-cost shops, you can rent a car only with 2,000-2,500 yen per day. It means that you could have saved your money by 2500 yen per day. When you rent a car at a well-known Rent-a-car company like HONDA, TOYOTA, and NISSAN, you will have to pay more.
As you indicated, these lavender fields in Furano and Biei are sightseeing spots specially tailored for tourists (not ordinary farms). They are basically like a botanical garden or something like that. Also, there is a problem in your guide book. Usually, tourist guide books describe everything in an exaggerated way to attract more tourists. You can see such exaggeration in every tourist guide book published around the world.
If you want to see lavender fields carefully managed by farmers, visit (someday in the future) less popular lavender fields, for example, Kurose Farm in Sunagawa City (Sunagawa is a minor city located in the middle of Sapporo and Asahikawa):
Kurose Farm (Kurose is the family name of a person managing this farm):
http://www.youtube.com/watch?v=7s1dShKV8Iwhttp://hokkaido-blog.com/archives/2006/07/post_419.htmltel: +81-125-53-2685
You can enjoy eating fresh vegetables grown in this farm with watching lavenders and tranquil views.
Anyway, don't take what you read in your guide books as it is. What you read there is a kind of exaggeration. Before you visit Hokkaido, ask someone living in Hokkaido for more appropriate information.
By asking someone in Hokkaido, you can get information on family farms open to public. Most of these family farms are small and have no Internet Web site for English-speaking tourists. Of course, even if you read your guide books again and again, you can not find such family farms.
As you see, visiting Shiretoko Five Lakes is getting more and more difficult and costs more and more these days due to its natural environment regulations and the risk of meeting wild bears. If you want to see great nature, avoid visiting sightseeing spots listed in your guide books. Most sightseeing spots listed in tour guide books are pouring down (crowded) because many tourists tend to visit the same spots listed there (you might be surprised to see that sightseeing spots not listed there are rather empty).
By the way, your trip to Japan seems to continue still now. Do you now stay in Matsumoto? If you stay in Matsumoto, visit a craft work street. Matsumoto is known as a city where unique crafts are produced by experienced artists:
http://www.youtube.com/watch?v=JbSFEiAKCUU